1. Field of the Invention
The present invention generally relates to expandable tubular with at least one centralizer. More particularly, the present invention describes an expandable tubular with at least one centralizer as an integral part of the tubular, its uses, and methods of making. Furthermore, this invention relates to a downhole tubular or downhole assembly, e.g., for use in an oil/gas well or a water well, and a method of completing a well.
2. Background of the Invention
In recent years, the use of expandable tubulars has become more common in the drilling and completion phases of well bore construction. In these phases, it is necessary to protect tubulars (e.g., casing, tubing, and/or seal bores) from scarring; and/or to protect sealing and anchoring devices; and/or to prevent the tubulars from being scarred while being run down hole. In some situations, it is desirable to preventing the tubulars from bending and/or egging when being handled.
In some cases, due to the limits of expansion of the expandable tubulars (e.g., casings and tubings), the outside/outer diameter (OD) of the tubular is as close as possible to the inside/inner diameter (ID) of the wellbore or casing. Rubber rings and other devices are either molded or attached to the expandable tubular to act as centralizers and seals after the tubular is expanded. The rubber rings may also serve to keep anchoring devices (anchors) attached to the tubular from scarring the casing and/or seal bores. During the expansion process, the anchoring devices (anchors) are pressed into the casing and hold the tubular in place; and the rubber rings or other devices would function as seals.
Because the OD of the tubing and seals and anchors is very close to the casing ID, if the tubing or seals touch the casing, the seals will compress below the tolerance of the anchors and damage the casing and/or seal bores. The anchors can also be dislodged causing more damage. In addition, the tubing and casing can be scarred causing it to split. When the tubulars are being handled, because the tubular material has little memory due to the high carbon content, it often eggs out of shape when it is picked up by a sling.
Accordingly, there is continuing need and interest to develop expandable tubulars/assemblies with improved centralizers.